15.8 - Sliding Filament Mechanism Flashcards
The structure of myosin and actin Changes in the sarcomere during muscle contraction The sliding filament theory Muscle relaxation The ATP-creatine phosphate system for providing energy
What is the structure of myosin?
Myosin heads have:
- A hinge enabling movement.
- One site for binding to actin.
- Another site for ATP binding, providing energy.
What is the structure of actin filaments?
*Sites for myosin head attachment, known as actin-myosin binding sites.
*Other regulatory proteins like tropomyosin attached.
What is the structure of myosin heads?
*A hinge enabling movement.
*One site for binding to actin.
*Another site for ATP binding, providing energy.
What happens to the sarcomere during muscle contraction?
I band and H-zone shorten
What is the sliding filament theory?
Explains muscle contraction at molecular level
What are the steps in the sliding filament theory?
Ca2+ moves tropomyosin
How does muscle relaxation occur?
Ca2+ returns to sarcoplasmic reticulum
What are the energy sources for muscle contraction?
Aerobic respiration
What is aerobic respiration used for?
Prolonged
What is anaerobic respiration used for?
Short
What is the ATP-creatine phosphate system used for?
Short bursts of vigorous exercise
